Superconducting vacuum bridge and preparation method thereof

Abstract

The invention discloses a superconducting vacuum bridge and a preparation method thereof. The preparation method comprises: coating a substrate with an LOR material in a spin coating manner to form anLOR sacrificial layer; coating the LOR sacrificial layer with a first photoresist in a spin coating manner, and carrying out mask exposure, wherein the mask exposure defines the positions of bridge piers; carrying out first development to obtain the three-dimensional structure of the bridge piers and a bridge arch; removing the unexposed photoresist from the bridge arch by using the difference inthe solubility of the first photoresist and the LOR material in acetone; carrying out temperature setting heating reflux on the LOR material at the bridge arch to obtain an edge arched bridge arch; sequentially coating the edge arched bridge arch with an LOR layer and a second photoresist in a spin coating manner; exposing the second photoresist, and carrying out second development; carrying outvacuum evaporating to form a superconducting metal layer; and releasing the LOR sacrificial layer positioned below the superconducting metal layer bridge arch and the structure positioned at the non-superconducting bridge to obtain a superconducting vacuum bridge. According to the present invention, the method does not require the process for exposure and removal of the photoresist by using the developing solution, is simple, and can prepare the superconducting vacuum bridge with the length of more than 10 [mu]m.

Description

technical field [0001] The disclosure belongs to the technical field of preparation and application of micron superconducting circuits, and relates to a superconducting vacuum bridge and a preparation method thereof. Background technique [0002] The air bridge is a circuit structure, which is a way to realize the bridge connection of the planar circuit in the form of a three-dimensional bridge. Due to the use of air as the dielectric between the two conductors, the operating frequency range of the line can be extended. Compared with the current circuit without air bridge, it can realize the connection of the plane waveguide ground wire and cross the plane waveguide, which can enhance the stability of the circuit and build a complex circuit structure, which is of great significance in micron superconducting microwave circuits. [0003] For superconducting circuits, they generally work in vacuum and at low temperature, so it is necessary to prepare superconducting vacuum bri...

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Problems solved by technology

Use PMGI as the preparation method of sacrificial layer, there are following problems: the first, need to carry out mask exposure and development to photoresist, in actual technology, only developing photoresist and not involving PMGI layer is difficult to control; , it is also necessary to carry out deep ultraviolet exposure and development of PMGI with a developer, and use the developer to remove the photoresist during the development of PMGI; the above process requires two exposures and development of the photoresist and PMGI respectively, At the same time, it also involves deep ultraviolet exposure and mask exposure. The degumming process is cumbersome and it is difficult to control the degree of development. It is easy to cause PMGI to be dissolved by the developer due to improper control of the development time, resulting in inconsistent bridge arch heights; The parameters of developing PMGI and removing photoresist cannot produce vacuum bridges with a length longer than 10 microns, therefore, the preparation method using PMGI as a sacrificial layer is no longer suitable for the preparation of superconducting vacuum bridges

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